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May 25
How to spot a leaking underground oil or septic tank

How to Tell If Your Underground Oil Tank is Leaking

As with almost everything, the technology used to heat homes and buildings evolves constantly. More efficient or environmentally-friendly methods of heating replace outdated methods that don’t meet the new standards. Unfortunately, adoption is not always universal. Older homes and buildings can be slow to make the switch. In Portland, we see this with underground oil tanks.

When underground heating oil tanks were first installed, they were cost-effective, efficient, and much more visually appealing for owners. Now, we know that burying oil in tanks is disastrous for the environment. Eventually, most (if not all) the tanks begin leaking in the soil, contaminating everything.

The worst part? It’s almost impossible to spot an underground leak until it’s been happening for quite some time. To try to help homeowners and buyers in the Portland area, we put together everything you should look out for if you’re wondering how to tell if your oil tank is leaking.

Signs Of A Leaking Oil Tank to Look Out for as a Homeowner

As we mentioned, oil tank leaks in the ground are very difficult to detect. It takes diligent work on your part as the owner. The first sign is your heat bill. Typically, the oil leak is slow and steady, so you won’t see an incredible jump from month to month. But take a look at your bill over a few months. If you notice a steady increase, it’s likely that your oil tank is leaking. Particularly in the summer months, when you’re rarely using your heating, you shouldn’t see a climb in costs.

Active oil leaks that have been going on for a while will also affect the smell of your soil. Homeowners who suspect a leak should try digging in the ground around your oil tank. If the distinct smell of oil shows up, you’ve got a leak. The longer your oil tank leaked, the wider the area will be of affected soil, which will end up costing you as the owner. Make sure to take the first step to remove your heating oil tank as soon as you suspect a leak to save yourself time and money.

Finally, a less common sign that your oil tank is leaking happens to your neighbors. Sometimes the heating oil tank leaks for so long that the oil reaches the water. Either your water or your neighbor’s water can become contaminated with oil. Obviously, this is the worst-case scenario and causes quite a few more steps to clean up. To avoid any major problems, try to be as proactive as possible with fixing or removing your underground heating oil tank.

Spotting a Leaking Heating Oil Tank as a Buyer

Of course, owners are not the only people who should be concerned with oil tank leaks. Buyers in the Portland area who want to purchase an older home shouldn’t inherit the problem of a bad tank. Luckily, there are ways to protect yourself while you’re house hunting.

First, tour the exterior of the house. If the home uses a heating oil tank, you’ll see a fill pipe as well as a vent pipe. They will connect to the house on one end. The other end of the pipe will either connect to the foundation wall or go directly into the ground. When a heating oil tank is removed, the fill and vent pipe are also removed. The holes leftover from the pipes must be filled in with concrete, so if you don’t see a pipe, the previous owners removed the oil tank.

In other cases, you may see a patch of the yard that either doesn’t grow grass at all or grows at a lower quality than the rest of the yard. That doesn’t always mean that a heating oil tank is in the ground, but it could be an indicator. Owners also use concrete slabs to cover the ground above the oil tank, so be on the lookout for that.

You can also ask local oil companies. They will have records of homes that are heated with an underground heating oil tank. With that information, you can do a little digging to find out if the tank has ever been maintained or replaced and when. Although we don’t advise that you keep the heating oil tank after you purchase the home, it can be used as leverage to lower the cost of the house.

Causes of Oil Storage Tank Leaks

With all the issues that heating oil tank leaks cause, you might be wondering how they start in the first place and if there’s a way to prevent them from happening. Unfortunately, there’s not an easy way to prevent them, especially if you’re dealing with an old tank.

In the ground, the steel that the heating oil tanks are made of reacts to the chemicals and water in the soil. In Portland, where the soil holds more moisture than most other places, the tanks are particularly susceptible to corrosion. The reactions create tiny holes in the steel where the oil can flow freely. If the leak goes undetected, these tiny holes can start to connect, creating bigger openings for more oil to escape.

This is also true for the pipes and connection points that carry the oil from the tank to your home. The wear and tear of being buried underground can cause rust and punctures over time so that a bigger area of your yard is affected by leaks.

Newer heating oil tanks are installed with protective tubing and covered with concrete to make the system last longer underground. But, even the most expert installation can still leak.

What to Do If You Think You Have a Leak? 

The first step to diagnosing a heating oil tank leak is to call a trusted professional. The process of removing the tank and cleaning up the oil takes precision and expertise. You don’t want to do this by yourself, especially if the oil has leaked to a large area of your property.

Once the tank has been removed, there are a few options for clean up based on the severity of the leak. At Alpha Environmental, we offer three options for you. The Soil Matrix Cleanups removes most of, if not all, the contaminated soil or covers low impact closures where limited contamination is present.

Our Risk-Based Decision-Making Cleanups allows closure with some of the contamination left on the property, as long as it can be proven to meet all necessary regulations for human and environmental health. We recommend this option for properties where the building would be impacted or the cost would be too high to use a full Soil Matrix Cleanup

Finally, we do offer a General Remedy Cleanup for low-risk sites that caught the heating oil tank leak early. This is your most cost-effective option and the one that can be done the fastest. No matter which option you choose, however, we can guarantee a safe, efficient, and complete project from the expert team at Alpha Environmental. If you’re ready to take care of your heating oil tank leak or want to talk to someone about how to diagnose your leak, contact us. We are more than happy to help you.

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Matthew Micheletty

About The Author

Matthew has been Alpha's Director of Operations for over four years. He works directly with our clients in effort to provide exceptional customer service as well as managing the day to day of the company. When he's not at the office, you can find him at Red Tail Golf Club or cruising PDX in one of his project cars.